11.1 Data source and scope

The source data covers every offender with any Corrections management history since 1980 and includes all of those offenders’ careers, even the parts of those careers that occurred before 1980. No information in this report is based on surveys or estimates; it is all based on historical operational records as stored electronically in Corrections’ databases (and supplemented with some historic ethnicity data from the Ministry of Justice).

The direct source of data for this report has been the newly developed (in 2006 and 2007) Offender-Major-Management-Period tables stored in the CARS (Corrections Analysis and Reporting System) data warehouse. These CARS tables in turn are derived from data stored in Corrections IOMS (Integrated Offender Management System) database, which is Corrections day-to-day operational database. IOMS has been in use since mid 1998 for prisons and early 1999 for community probation services. At start up of IOMS, historic data was imported from Corrections legacy databases and also from the Law Enforcement System (LES). LES was originally known as the Wanganui Computer system. It was a Justice sector-wide system that was used nationally from 1976 until after 2000 and it was eventually decommissioned in 2005. When LES started in 1976 all new offender, offence and sentence details were entered into the system and a back-loading exercise took place to ensure current offenders at the time were entered along with all their previous history. The author understands that for some years after the initial start-up, as recidivists came to the attention of the sector, their new offences were loaded and also an effort made to enter the offenders earlier offence and sentence history.